Publication: Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study
Accepted Date
2014-01-24
Issued Date
2014-04-24
Copyright Date
2013
Resource Type
Language
eng
ISSN
1549-1277 (printed)
1549-1676 (electronic)
1549-1676 (electronic)
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Mahidol University
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PLoS medicine
Bibliographic Citation
Carrara VI, Lwin KM, Phyo AP, Ashley E, Wiladphaingern J, Sriprawat K, et al. Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study. PLoS Med. 2013;10(3):e1001398.
Suggested Citation
Carrara, Verena I., Lwin, Khin Maung, Phyo, Aung Pyae, Ashley, Elizabeth, Wiladphaingern, Jacher, Sriprawat, Kanlaya, Rijken, Marcus, Boel, Machteld, McGready, Rose, Proux, Stephane, Chu, Cindy, Pratap Singhasivanon, ประตาป สิงหศิวานนท์, White, Nicholas, Nosten, Francois Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study. Carrara VI, Lwin KM, Phyo AP, Ashley E, Wiladphaingern J, Sriprawat K, et al. Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study. PLoS Med. 2013;10(3):e1001398.. doi:10.1371/journal.pmed.1001398 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/695
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Title
Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study
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Abstract
BACKGROUND: The Shoklo Malaria Research Unit has been working on the Thai-Myanmar
border for 25 y providing early diagnosis and treatment (EDT) of malaria.
Transmission of Plasmodium falciparum has declined, but resistance to artesunate
has emerged. We expanded malaria activities through EDT and evaluated the impact
over a 12-y period.
METHODS AND FINDINGS: Between 1 October 1999 and 30 September 2011, the Shoklo
Malaria Research Unit increased the number of cross-border (Myanmar side) health
facilities from two to 11 and recorded the number of malaria consultations.
Changes in malaria incidence were estimated from a cohort of pregnant women, and
prevalence from cross-sectional surveys. In vivo and in vitro antimalarial drug
efficacy were monitored. Over this period, the number of malaria cases detected
increased initially, but then declined rapidly. In children under 5 y, the
percentage of consultations due to malaria declined from 78% (95% CI 76-80)
(1,048/1,344 consultations) to 7% (95% CI 6.2-7.1) (767/11,542 consultations),
p<0.001. The ratio of P. falciparum/P. vivax declined from 1.4 (95% CI 1.3-1.4)
to 0.7 (95% CI 0.7-0.8). The case fatality rate was low (39/75,126; 0.05% [95% CI
0.04-0.07]). The incidence of malaria declined from 1.1 to 0.1 episodes per
pregnant women-year. The cumulative proportion of P. falciparum decreased
significantly from 24.3% (95% CI 21.0-28.0) (143/588 pregnant women) to 3.4% (95%
CI 2.8-4.3) (76/2,207 pregnant women), p<0.001. The in vivo efficacy of
mefloquine-artesunate declined steadily, with a sharp drop in 2011 (day-42
PCR-adjusted cure rate 42% [95% CI 20-62]). The proportion of patients still
slide positive for malaria at day 3 rose from 0% in 2000 to reach 28% (95% CI
13-45) (8/29 patients) in 2011.
CONCLUSIONS: Despite the emergence of resistance to artesunate in P. falciparum,
the strategy of EDT with artemisinin-based combination treatments has been
associated with a reduction in malaria in the migrant population living on the
Thai-Myanmar border. Although limited by its observational nature, this study
provides useful data on malaria burden in a strategically crucial geographical
area. Alternative fixed combination treatments are needed urgently to replace the
failing first-line regimen of mefloquine and artesunate.